A Russian millionaire who has made the North his engineering powerbase was among the guests at a private Tory dinner – and paid £90,000 for a bronze bust of David Cameron.

Alexander Temerko, the man behind Tyneside offshore firm OGN, was at an exclusive party funders’ dinner in which businessmen and women with a total wealth of more than £11bn were wooed by David Cameron and the Tory cabinet.

A leaked rich list has shown who sat where at an Old Billingsgate market fundraising dinner. Mr Temerko, already making a name for himself as one of the biggest Tory party backs in the North, was on the relatively cheap Eric Pickles table, with seats at £1,000-a-head.

With him was David Edwards, chief executive of Mr Temerko’s company and strip club owner Peter Stringfellow, among others.

Mr Temerko has made personal and company donations to the Conservatives of around £474,555. The businessman, who became a British citizen in 2011, has made a name for himself in the North with donations worth more than £10,000 to Stockton South MP James Wharton. Another £5,000 has gone to the Berwick Tory campaign effort.

At the exclusive Tory dinner, Mr Temerko ended up as the star of the showing in an unexpected bidding war for a bronze bust of David Cameron.

It was valued by the artists Nadey Hakim at £12,000 but wealthy Mr Temerko ended up paying £90,000 for it. Instead of keeping it though, it is reported Mr Temerko donated the bust to the Carlton Club, the home of the Conservative establishment in London’s St James’s.

The Prime Minister showed how happy he was with the sale when he went over to Mr Temerko and thanked him, slapping him enthusiastically on the back.

Details of the party, held in 2013, only emerged after the guest list was leaked. The lack of transparency over meetings between rich business heads and MPs has already led to calls for a bit more honesty.

“Cameron is trying to buy his way to power,” said Jon Ashworth, the shadow Cabinet Office minister. “We will be demanding to know who is whispering in his ear.”

Darren Hughes, deputy chief executive of the Electoral Reform Society, said the revelations were “the latest demonstration of why we need a new, more transparent system for funding political parties”.

Middlesbrough South and East Cleveland Labour MP, Tom Blenkinsop, said: “Isn’t the fact the Prime Minister isn’t declaring this another illustration of he and Number 10 operate.

“Knowingly employing a spin doctor when warned about phone hacking, associating in Europe with a Dutch party that banned female members till 2006 and a party in Finland that is openly homophobic, employing Lunton Crosby a know tobacco lobbyist and now still hiding guest lists and donations from Russian oligarchs and big business. This is a prime minister who stands up for the special interests of a rich elite.”

Mr Temerko was allowed to stay in Britain after a judge ruled an attempt to extradite him to Russia on fraud charges was politically motivated, and as such he is allowed to make political donations.

A spokesperson for Mr Temerko has already said that the Russian supported the Conservative party as a member, and added: “He promotes and is actively involved in the party’s election campaign.”

A Tory spokesman said of the summer party: “All donations to the Conservative party are properly and transparently declared to the Electoral Commission, published by them, and comply fully with Electoral Commission rules.”